Adding reCaptcha to your affiliate front-end forms such as your signup form, contact form, etc. is easy to do. We use Google v3 reCaptcha for the forms and the setup can be found in your iDevAffiliate admin center at System Settings (top menu) then General Settings then General Settings (tab). At the bottom of the settings form on this page, you will find a section that is grouped by color, specific for the reCaptcha settings. Here is where you will enable reCaptcha but also generated and insert your Google reCaptcha keys.
NOTE: The most common thing we see in the support desk is enabling reCaptcha but not entering in the Google keys. The Google keys are required for the Google reCaptcha to work.